This invention relates generally to underground storage reservoirs in combination with above-ground shelters for accessing such reservoirs, and more particularly relates to an integrated underground fluid storage reservoir and above-ground canopy support system.
Various types of materials are stored beneath the surface of the ground for access through above-ground dispensing and/or distribution facilities. One class of such materials includes fluids such as fuels for automotive and heating uses. Typically, these storage installations include a fluid reservoir that is buried beneath ground level within an excavated pit. A backfill material is typically used to surround the storage tank to achieve a buried condition for the reservoir. Pea gravel is a standard backfill material in the industry because of its ability to quickly achieve a substantially settled condition. Sand has also been used as a backfill material.
In the case of underground storage reservoirs at automobile service stations, one or more reservoirs containing automobile fuel are typically located upon the service station premises at a location some distance away from the pumps used for dispensing the fuel to automobiles. In such an arrangement, the underground storage tanks can be filled, such as by tanker trucks, without impeding the ability of the service station to continue operating. This is because the tanker trucks can access ports or manholes for filling the underground storage tanks in the remote area of the service premises away from the dispensing units.
However, locating underground storage tanks for fluids such as automobile and heating fuels at a distance away from the dispensing location requires a significant amount of underground piping for connecting the dispensing units to the underground storage tanks. These pipes sometimes require maintenance and/or service operations. Therefore, these pipes must be accessible to service and maintenance personnel at times. A typical automobile service station, however, includes one or more sections of concrete driveway covering a substantial portion of the service station premises, in order to provide customers with sufficient maneuvering access to the typical several dispensing units. This substantial concrete driveway also provides sufficient access to the underground storage reservoir filling ports by tanker trucks. This type of arrangement, however, makes accessing the underground piping network connecting the storage tanks with the dispensing pumps expensive, difficult and time consuming.
Automobile service stations are often designed to include multiple dispensing units, commonly referred to as xe2x80x9cpumps,xe2x80x9d xe2x80x9cmultiple pump dispensersxe2x80x9d or xe2x80x9cMPDsxe2x80x9d, from which multiple customers can access the underground storage reservoir or reservoirs at the same time. These dispensing units are often located at multiple service islands located upon the service station premises. Since automobile fuel is commonly sold in multiple grades, the different fuel grades can be stored within a single partitioned reservoir or within multiple reservoirs. Extensive underground piping is therefore typically required in order to distribute different grades of fuel to the different dispensing units located at the various service islands.
In addition, the increasingly popular recovery of fuel vapors from automobile fuel tanks upon filling involves the transport of these vapors to the underground storage reservoir (Phase II recovery). These vapors are subsequently transported to a tanker truck during the next filling of the underground storage reservoir (Phase I recovery). Thus, additional extensive piping would need to be located underground for vapor recovery from the dispensing units located at multiple service islands.
It is also desirable for automobile service stations to provide customers with at least some limited form of shelter from the weather, especially from precipitation. Service stations commonly provide one or more large canopies that extend over a substantial portion of the service station premises, covering the multiple service island locations as well as an extended amount of area surrounding the dispensing pumps. In this manner, service station customers are provided with the convenience of being able to stay dry while fueling, as well as while entering and exiting vehicles. Often, the canopy extends to provide a covered walkway to the service station attendant, who is commonly located within an adjacent service building, such as an automobile service garage or convenience store.
The canopies are typically suspended in place at some distance above the ground through the use of multiple support columns. These columns are often positioned adjacent the dispensing units upon one or more service islands upon the service station premises. Positioning the canopy support columns in this manner allows maximum maneuverability for automobiles upon the service station premises.
Further, the recent increased emphasis on environmental concerns has focused attention on the nature of, and environment surrounding, the underground storage reservoirs to minimize the leaking of fluids stored therein. A majority of conventional steel underground storage tanks are believed to leak due to electrolysis along the bottom of the tank. This is caused at least in part because the ground at the bottom of the tank is often wet and the weight of the tank and its contents cause solid contact with the soil, resulting in a condition that is favorable to the flow of electric current. Also, during such environmental events such as earthquakes and hurricanes, shifting of the underground storage reservoir, the pea gravel, sand or other fill material surrounding the tank, or introduction of excessive amounts of water to the area surrounding the tank, can each have negative effects on the tank, including leakage of the tank itself and leakage from the fluid delivery system due to disruption of the alignment of the delivery system relative to the reservoir.
A need therefore exists for an improved system whereby the need for extensive underground piping connecting underground fluid storage tanks and dispensing units can be eliminated. A need also exists for a simpler vapor recovery system for use in automobile service stations. A need also exists for an improved, simpler, less expensive system for constructing service station premises. A need further exists for an improved underground storage reservoir system having increased leak resistance, as well as increased resistance to the effects of earthquakes and hurricanes.
The present invention therefore provides an integrated underground storage reservoir and above-ground canopy system. The system includes a storage reservoir suitable for being buried beneath ground level and suitable for containing a fluid. The system also includes a support system including at least one support member that is disposed in communication with, or adjacent to, the reservoir and projects above ground level. Each support member is operable to support one or more canopies for providing shelter from the weather while accessing the reservoir.
More specifically, the integrated system of the present invention comprises an underground storage reservoir for the storage of fuel, such as automobile fuel or heating fuel. The integrated system further includes a support system including at least one support unit disposed in communication with the underground storage tank. In one preferred embodiment, a plurality of support units are disposed in contact with the underground storage reservoir and extend above ground level in a substantially vertical orientation. The present invention may include one or more underground storage reservoirs, any of which may be partitioned to hold more than one type or grade of fluid. In another preferred embodiment, the support system includes multiple support units disposed adjacent to the underground storage tank. The support units are preferably oriented in a generally vertical direction and protrude above the ground level. Thus, the support units are able to support at least one canopy for sheltering the dispensing unit area from weather while accessing the underground storage reservoir or reservoirs.
The present invention also includes a delivery system for delivery of the fluid from within the underground reservoir to above-ground level. Preferably, this includes one or more pipes disposed within the reservoir, which extend in a substantially vertical orientation to an above-ground location directly above the reservoir. The delivery system may also include one or more submersible pumps for delivering fluid from the reservoir to an above-ground location.
The present invention further includes a distribution system for the distribution of fluid from the delivery system. The distribution system may preferably include one or more distribution heads, each located in above-ground communication with one of the submersible pumps. The distribution system also preferably includes a piping network that extends from the distribution heads to one or more dispensing units on an above-ground or below-ground basis. Most preferably, the piping network is constructed to connect the various distribution units among one or more service islands by being routed through one or more of the canopies, described in more detail below. This piping network may therefore travel vertically from the distribution head or heads to a canopy along the external surfaces of the dispensing units, along the internal surfaces of the dispensing units, or along the support units. The above-ground nature of the distribution system allows easy access for service and maintenance purposes.
The present invention also provides an improved storage reservoir assembly having increased resistance to leakage of fluid from the assembly into the ground. The assembly includes a reservoir suitable for being buried beneath ground level and for containing a fluid and an enclosure suitable for partially surrounding the reservoir and supporting the reservoir from beneath. The enclosure is spaced from the reservoir so as to define a void between the reservoir and the enclosure. The void is filled with a filling material suitable for decreasing leakage of fluid into the ground and/or assisting maintaining the buried condition of the reservoir within the ground. The improved storage reservoir assembly preferably further includes at least one support unit connected to the reservoir and suitable for attachment to an above-ground canopy.
It will be appreciated that the present invention is also intended to include those features commonly associated with automobile service stations and fuel delivery stations, as are required for convenience and/or safety. Many of these features, such as venting and vapor recovery provisions, are provided in improved form in accordance with the present invention. While the description herein is intended to emphasize those features of the present invention that are advantages over the prior art, it is not intended to exclude other convenience and/or safety features.
An advantage of the present invention is to provide an integrated system whereby one or more underground storage tanks are located directly beneath an associated delivery and distribution system, thereby minimizing the amount of underground piping network that must be accessed for service and/or maintenance.
Another advantage of the present invention is to provide a integrated system whereby a fluid distribution system is located above ground level, to allow servicing and/or maintenance of the distribution system.
Another advantage of the present invention is to provide a simpler, less expensive system for providing an underground storage reservoir that can be accessed for both delivery and withdrawal while being protected from the weather.
Another advantage of the present invention is to reduce pollution by providing for the recovery of vapors from automobile fuel tanks and from underground storage reservoirs in a manner that is convenient, less expensive, requires a minimum amount of associated underground piping and includes above-ground equipment.
Another advantage of the present invention is to provide an integrated support system for the support of one or more canopies to shelter the accessing of an underground storage reservoir from weather, wherein the support system is disposed in communication with, or adjacent to, the underground storage reservoir.
Another advantage of the present invention is to provide an improved storage reservoir assembly having increased resistance to leakage of fluid from the assembly into the ground, due to both the local environment of the storage reservoir and the effects of environmental events such as earthquakes and hurricanes.